When a connector of an EVSE is connected to perform a charging procedure while a vehicle ignition is turned off, a control power source of a charger mounted in the vehicle needs to be turned on. However, it may be difficult to directly turn on the control power source using a signal provided in a charge standard for chargers (e.g., SAE J1772™ (SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charge Coupler)). Instead, the EVSE may transmit a CP signal to the charger. Because the CP signal is a pulse width modulation (PWM) signal, it may be difficult to maintain an on-state of the control power source of the charger using the CP signal.
Accordingly, in the related art, the following two methods are typically used:
First, a control power source may be enabled using a CP detection circuit that operates at all times independently of the control power source. Second, a sub-power source may be initially turned on in response to an input of a CP signal, may process the CP signal, and then continue to generate a signal to enable the control power source to operate. In the first method, a large number of issues can occur due to dark current and the like. Meanwhile, in the second method, various methods may be used to configure a circuit; however, issues associated with a response, reliability, and distribution of the circuit due to an analog circuit may occur. Additionally, the number of circuits may exponentially increase due to additional functional requirements. For example, malfunctioning may be highly likely due to a change in a duty condition of the CP signal, a change in an input voltage condition, or an inflow of noise.